This enables OSP (Operate on Second Packet) for GMAC4. The feature
allows DMA to fetch second descriptor while its still processing the
first one.
Running iperf, the performance gain is +/- 38%.
Signed-off-by: Jose Abreu <joab...@synopsys.com>
Cc: David S. Miller <da...@davemloft.net>
Cc: Joao Pinto <jpi...@synopsys.com>
Cc: Vitor Soares <soa...@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavall...@st.com>
Cc: Alexandre Torgue <alexandre.tor...@st.com>
---
drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
index 117c3a5..9aab5b3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
@@ -94,6 +94,10 @@ static void dwmac4_dma_init_tx_chan(void __iomem *ioaddr,
value = readl(ioaddr + DMA_CHAN_TX_CONTROL(chan));
value = value | (txpbl << DMA_BUS_MODE_PBL_SHIFT);
+
+ /* Enable OSP to get best performance */
+ value |= DMA_CONTROL_OSP;
+
writel(value, ioaddr + DMA_CHAN_TX_CONTROL(chan));
writel(dma_tx_phy, ioaddr + DMA_CHAN_TX_BASE_ADDR(chan));
--
1.7.1
